Benefits of Exercise

We have all heard that exercise (aerobic activities, anaerobic exercise or weight training) is good for us. Regular physical activity aids weight loss, keeps us healthy and in shape, lets us sleep better and, in turn, makes us more alert and improves our mood, amongst other kinds of health benefits.

But what really happens if we are forced to ​take a break from exercise? What do our bodies really go through during extended periods of inactivity? ​

Aerobic Exercise Versus Strengthening Exercise

For many people, exercise can take many forms – from a short brisk walk to intense workouts at the gym. However, there are broadly two categories of exercise, namely aerobic (endurance) and strengthening or resistance-based exercises.

Endurance or aerobic workouts such as running, cycling or brisk walking benefit a person's overall health as they can improve heart health and circulation. Resistance exercises such as weightlifting improve cardiovascular health, builds muscle and strength, and other health parameters.​ ​

​When one engages in regular endurance exercise, four benefits can be observed:

  1. An increased ability of the heart to pump blood
  2. The blood vessels become more efficient in sending blood to where it is needed
  3. The number of vessels that deliver oxygen and “food” to the muscles is increased
  4. Increased size and number of mitochondria, which are the “batteries” of our cells as they provide them with energy for their functions​

​In essence, when one exercises more and more, the body will experience a heightened efficiency in the use of oxygen as well as nutrients, and that ​is how one feels “healthier” or gets that proverbial glow.

​Stopping Exercise for Too Long

​​Some individuals who used to exercise regularly may experience periods of inactivity due to injuries, stressful work schedules or the lack of motivation. A common term for such a group of people is “apparently healthy but deconditioned individuals”.

A person who used to run five kilometres in 20 minutes will find that their timings slow by approximately 10 seconds in just a week of inactivity. After two weeks, regular runners may begin to experience a reduction in muscle power and be slower by one minute in their run times. With between 14 to 30 days' of inactivity, a 12 percent reduction in performance and a noticeable decrease of muscle power can be seen.

When one stops exercising, aerobic fitness is among the first things to go. Physical inactivity begins to produce its negative effects very quickly, especially for older adults.

“The elderly can decondition very quickly,” says Dr Cindy Lin, Senior Staff Registrar at the Changi Sports Medicine Centre. “Even after just a few days on bed rest, they can have significant functional declines such as going from being fully independent to not being able to walk without assistance or requiring a wheelchair for mobility and needing assistance with activities of daily living. The high likelihood of deconditioning from a sedentary lifestyle in the elderly makes it even more important that they stay physically active on a regular basis, so they don't lose their physical capabilities that keep them happy, active and involved in life.”

Important to Remain Active

Despite the positive mental and physical benefits of exercise, long-term adherence to exercise programmes remain challenging, as an estimate of only 50 percent of all persons who begin an exercise programme will continue the habit for more than six months. It is common knowledge that a sedentary lifestyle can lead to many problems such as diabetes, heart diseases, and problems with joints and ligaments, not to mention weight gain. There are also the psychological effects of physical inactivity to consider – a lack of exercise has been shown to be associated with depression and lower self-esteem.

Part of that has to do with blood flow (again, oxygen) to the brain, as more oxygen equals better brain function. Furthermore, exercise is actually a form of stress – but a good, controlled one – that is used to train your body to handle increased oxygen demand as well as increased levels of stress hormones such as norepinephrine. By exercising, you desensitise the norepinephrine receptors, which means that it will take higher concentrations of these hormones to feel stressed. Hence, it is very important to stay physically active, even for individuals who might have been off rigorous training programmes for varied reasons, such as wanting to avoid injuries.

Alternative activities that are of a lower intensity such as riding a stationary bicycle, elliptical or rower can help the body maintain some level of fitness. These lower-intensity activities give the muscles a different kind of break but one that will not cause them to lose that much aerobic fitness.

To get a full assessment of your fitness and the level of intensity that you should undergo for maximum results when exercising, please consult your doctor or trainer.

Read the original print article titled When We Stop Movin', Movin' (PDF).

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